Sökning: "stars: imaging"
Visar resultat 1 - 5 av 16 avhandlingar innehållade orden stars: imaging.
1. Magnetic fields of cool active stars
Sammanfattning : Magnetic fields are present throughout the universe and are very important for many astrophysical processes. Magnetic field influences a star throughout its life and affects nearby objects such as planets. LÄS MER
2. Magnetic fields of cool stars from near-infrared spectropolarimetry
Sammanfattning : Magnetic fields rule many physical processes in and around stars throughout their lifetime. All cool stars possess a magnetic field, likely generated by dynamo processes. In order to properly understand the evolution of cool stars, we need to understand their magnetism. LÄS MER
3. Magnetic fields and chemical maps of Ap stars from four Stokes parameter observations
Sammanfattning : Our knowledge of stellar magnetic fields relies almost entirely on circular polarization observations, which has historically limited our understanding of the stellar magnetic field topologies. Recently, it has become possible to obtain phase-resolved high-resolution spectropolarimetric observations in all four Stokes parameters for early-type magnetic stars. LÄS MER
4. Crowded Field Photometry and Luminosity Function Analysis as Probes of Galactic Evolution
Sammanfattning : Crowded field photometry is a powerful method to investigate stellar evolutionary processes in astrophysically interesting regions such as nearby external galaxies and globular cluster cores. While detectors are approaching the physical limits for photon detection, data analysis methods for crowded stellar fields are not yet equally sophisticated. LÄS MER
5. Magnetic and Chemical Structures in Stellar Atmospheres
Sammanfattning : We present an investigation of the magnetic field geometries and inhomogeneous distribution of chemical elements in the atmospheres of peculiar A and B stars. Our study combines high-quality spectroscopic and spectropolarimetric stellar observations with the development and application of novel techniques for theoretical interpretation of the shapes and variability of stellar line profiles. LÄS MER